Conventionally, as an electronic component housing package in which an electronic component such as a piezoelectric oscillation device or a semiconductor device is mounted, an electronic component housing package provided with a mounting section for mounting an electronic component on an insulating substrate made of a ceramic sintered body or the like has generally been used. A lid body is joined to an upper surface of the insulating substrate so as to cover the mounting section. Such an electronic component housing package includes the insulating substrate having a plate-shaped base and a frame-shaped frame; and wiring conductors formed to extend from the mounting section to a lower surface of the base and the like, the base having the mounting section for the electronic component on an upper surface thereof, and the frame being laminated on the upper surface of this base so as to surround the mounting section.
Of the wiring conductors, the wiring conductor provided in the mounting section functions as a connection pad to which the electronic component is connected, and the wiring conductor provided on the lower surface of the base (a lower surface of the insulating substrate) functions as a conductor for external connection (an external connection conductor) when being mounted on a module substrate. Then, after the electronic component is mounted in the mounting section and each electrode of the electronic component is electrically connected to the connection pad, the mounting section is sealed by the lid body and the like, and an electronic apparatus is thereby produced. In addition, a frame-shaped metallized layer is formed on an upper surface of the frame, so as to join the lid body made of metal thereto. In this electronic component housing package, the lid body is joined to the frame-shaped metallized layer by a sealing material such as silver solder, and the electronic component is thereby hermetically sealed in the mounting section.
Here, in order to prevent oxidation corrosion and facilitate the connection with the electronic component, the connection with the module substrate by solder or the like, and the like, a nickel plating layer and a gold plating layer are sequentially deposited on each of the wiring conductors of the electronic component housing package such as the connection pad which is exposed therefrom. In order to deposit the plating layers on each of the wiring substrates, the following technique is adopted. For example, such a structure is prepared that a through hole is provided in an outer periphery of each wiring substrate region formed and arranged in a matrix substrate and becoming the electronic component housing package, that an inner surface conductor is provided on an inner surface of this through hole, that a through conductor is provided near the outer periphery of each of the wiring substrate regions, that a connection conductor extending across the adjacent wiring substrate regions so as to connect the through conductors is provided, and that the wiring substrate regions are integrally connected via the inner conductors, the connection conductors, and the like. Then, the plating layers are deposited on the wiring conductors of each of the wiring substrate regions that are exposed therefrom by an electroplating method in which electricity is supplied to all of the wiring conductors formed in the matrix substrate. Note that, since a division groove is formed between two each of the wiring substrate regions on both surfaces of the matrix substrate so as to oppose each other, the connection conductors are provided in an inner layer of the insulting substrate so as to prevent cutting thereof by formation of the division grooves (see Japanese Unexamined Patent Publication JP-A 2005-50935).